Better Left Unsaid
by SerenBex
Summary: Five times things were left hanging in the air, but one time they weren't...
1. Chapter 1

Since the last incident with the Zygon population of Earth, and Kate's latest bout of amnesia, the UNIT boss had realised that there was a huge difference between the two Osgoods that she saw in front of her. Kate was convinced that she could, now, tell them apart; which was Human Osgood and which was Zygon Osgood. They still, however, refused to answer her, both stubbornly announcing that they were simply Osgood.

Kate wasn't sure what it was, but she knew instantly which Osgood had walked into her office, just by the way they looked at her. Before the latest incident that had led to blank memories, she hadn't ever been able to spot a telling difference between the two women. Now, though, there was an almost cocky smirk constantly in place on the face of the woman who the blonde was sure was Zygon, whilst her sister seemed to shift nervously from foot to foot in her presence. The Human Osgood never seemed completely at ease with her, anymore, something that made Kate inexplicably sad.

A knock on her office door drew the blonde out of her daydream and she jumped slightly in her seat, the movement dislodging her glasses from the end of her nose. They clattered onto the surface of the desk and she scooped them up, calling for whoever was waiting outside to come in. Osgood pushed her way inside, the smirk on her face broadening as Kate replaced her glasses and peered questioningly at her over the rims, giving the older woman a hint that it was the Zygon version she would be addressing.

"I've got the results of those tests we ran on the meteor that fell in Swindon." Osgood told her slowly, her head tilted slightly to one side.

"And?"

"It's composed of a completely new compound. Early indications suggest that it could be from a whole different galaxy altogether."

"Right… so why are you looking at me like that?" Kate asked, leaning back in her chair and arching an eyebrow.

"Like what, Ma'am?"

"Like there's something you know that I don't."

Osgood smirked again and shook her head. "I'm not sure what you mean, boss." She tilted her head again, her eyes roving over the blonde's face. "By the way, I'm loving the glasses… I'm not sure if I've mentioned that before."

Kate rubbed her forehead agitatedly, not having time to play games with her assistant at the moment. "Whatever you're thinking, Osgood, please spit it out."

"It's not _me_ who's thinking anything." The other woman replied cryptically, sending her a suggestive wink as she left the office.

Osgood, formally Bonnie, chuckled as she caught sight of Kate's totally bewildered face before she closed the door firmly behind her. She had only made it halfway back to the lab where she had left her sister, when the woman in question appeared in front of her. Pulling her inhaler out of her pocket and taking a quick puff, the human Osgood sent her sister a furious scowl, grabbing her by the wrist and pulling her to the side of the walkway to let another scientist pass them.

"What have you just done?" She demanded in a low voice, uncertainty and concern flashing in her eyes.

"Nothing!" Her sister replied innocently. "I took Kate the test results she requested."

"And? What else did you do? I know you did something you knew I wouldn't approve of because you blocked me out."

The more mischievous of the pair shrugged. "I may have complemented her choice of eyewear." At the sound of an incredulous splutter from the other woman, she chuckled. "What? I'm in your head, remember? I know exactly what you're thinking and I know exactly how dirty your thoughts are every time you see–"

"Stop!" The Human Osgood almost pleaded; terrified that someone would overhear what her sister was saying.

"You've gotta tell her sis… I think she's far cleverer that I gave her credit for. I think she's worked out which of us is which…"

"How?"

"Probably because you can't look her in the eye without turning crimson and needing your inhaler." The Zygon pointed out with a chuckle. "Your crush is absolutely adorable, but it does make this whole 'which of us is Human and which is Zygon' thing incredibly obvious."

Osgood huffed. "Why couldn't the Zygon Osgood have a crush on Kate?"

"Ah ha!" Her sister laughed triumphantly, turning and heading back towards their lab. "You admitted it!"

"There seems little point trying to deny it." She groused, following along the corridor.

"Besides, it wouldn't be the Zygon Osgood because I have _far_ more sense than to lust after humans…"

"How do you know that Kate knows which of us is which, anyway?" Osgood continued, unwilling to let the topic drop.

"Well… I'm guessing that there wasn't as much of a difference between you and the last Zygon-Osgood as there is between us. Everyone always seems surprised by how different we are." She reasoned. "Then there's the fact that every time Kate wants one of us to accompany her anywhere she asks you. Literally. The only time I get to leave this lab is if Kate's not going or someone else asks, otherwise it's always you."

"That's not…" Osgood trailed off as she thought about what her sister had said and realised that she was right. "OK… but that's not… Do you think she knows I…?"

"Either Kate is prejudiced against non-Humans or she just wants to keep you, specifically, near her." The Zygon scientist let out a long sigh and turned to face the other woman sympathetically, leaning against the workbench behind her. "Look… to be honest with you, I think Kate is as clueless about the whole thing that's blatantly going on between you as you are."

"What thing? There isn't a _thing_? Kate's our boss and I–"

She stopped speaking abruptly and turned a deep shade of crimson as the woman that was at the centre of their half-argument peered in at them through the glass in the door to their lab. She smiled as she caught their eyes, a flicker of confusion entering them as one Osgood smirked and the other looked terrified.

"Now's your chance, sis. Tell her how you feel. Or, at least, ask her out for coffee or something… anything so that I don't have to put up with the constant 'Kate is so great… she's so smart and so beautiful and I think I love her' monologue that rattles around in your head."

"It does not."

"It really does." The Zygon chuckled at her sister's petulant expression. "You'd better see what she wants before she realises we're talking about her."

As a flash of panic flitted across Osgood's face, the other woman headed to the other end of the lab, blocking the link between them in order to give her sister and Kate some privacy. She watched surreptitiously, pretending to be checking the contents of several glass flasks and boiling tubes. With a shake of her head, she cringed inwardly as the other brunette leant against the workbench in, what she guessed was supposed to be a casual movement, knocking a rack of test tubes to the ground in the process.

"Oh God!" Osgood mumbled, crouching down and starting to pick up the shards of glass. As Kate bent to help her, she held out a hand. "No, don't… you might cut yourself."

"So might you." The blonde reasoned, raising an eyebrow and sending her subordinate a crooked smile.

"Yes but I… well… I'm not you, so…"

Kate frowned. "What does that matter?"

"Well, I'm not the Head of Scientific Research, am I? I'm just me…" She chuckled nervously. "Just Osgood… well, not even the only Osgood. I'm _an_ Osgood."

"Osgood, stop." The blonde ordered. "You are not just an Osgood. You are…" She trailed off, unsure where she was heading with her statement… or confession. All Kate knew was that she wanted to completely remove the self-doubt and insecurity from the woman who was peering at her as though she was the answer to everything. "You're you."

Kate almost winced as the words left her mouth. They were nowhere near enough express what she really wanted to say, but she wasn't completely sure what that was either. If she was totally honest with herself, Kate hadn't worked out exactly what it was that she felt every time that she was in Osgood's company and she was long past fooling herself into thinking that the brunette was on her mind so often because she was her protégé. It went deeper than that, but the UNIT Head wasn't quite ready to examine her feelings just yet.

Instead, she straightened up and smiled at the younger woman. "I've asked McGillop to bring the samples down as soon as they arrive from the site."

"Thanks, Ma'am." Osgood nodded, looking slightly deflated.

As soon as she was out of the laboratory, Kate closed her eyes for a moment and let out a deep breath. Then she pulled herself together, marching back to her office to take out her frustration on whoever was behind the email she had received just before she had left to speak to the Osgoods. It was not a good day to request UNIT tightened their budgets.

* * *

 _ **So... I've become a little bit obsessed with Kate/Osgood and it exploded out of me like this! The more stories about them the better, in my opinion!**_

 _ **It's set a short while after the Zygon Invasion/Inversion, if you hadn't already realised that! :)**_

 _ **I hope you enjoy it!**_


	2. Chapter 2

Kate glanced up from her desk at the sound of a murmured conversation taking place outside her office. Her forehead furrowed as she tried to work out what was happening, catching sight of her assistant hovering on the other side of the glass panel, which was only partially blocked by the horizontal slats of the blinds. Osgood was clutching a couple of files tightly, almost like a shield, as she spoke to another of the scientists; a young man called Simon, as far as Kate could recall.

After a couple of moments, a light knock met her ears and The UNIT boss called out to encourage whoever was on the other side of the door to come in. The young brunette, who Kate spent the majority of her time at work with, entered the room and sent her a warm smile. Osgood crossed the office quickly and set the files down on the desk in front of her boss. Kate tilted her head and scrutinised her carefully, taking in the slightly more put-together appearance of the young woman than she was used to.

"You look… different." Kate told her, still trying to deduce what, exactly, was unusual about her assistant's appearance.

"Oh," Osgood blushed lightly, "thank you. I… Well, actually, I've got a date."

The older woman wondered, for a moment, whether she'd misheard. Something inside her twisted uncomfortably and she swallowed hard, forcing herself to remain nonchalant. She wondered why she had reacted so strongly to the thought of Osgood seeing someone. The obvious answer hit her like a truck, but Kate dismissed it; deciding to put the feeling down to worry that with the distraction her dedicated right-hand wouldn't be quite so committed anymore.

"Oh… Right. Well, lovely…" She mumbled, struggling to keep her tone even.

There was a long pause where the two women just looked at each other, apparently neither of them really knowing how to proceed with the almost stifling atmosphere that had filled the space between them. Osgood chewed the inside of her cheek and twisted her hands nervously. She opened her mouth several times to speak, but closed it again abruptly as she realised that she had no idea what to say.

Kate, too, was struggling to think of something to break the ice between them. She had about a hundred questions bouncing around in her mind, but she couldn't seem to force any of them out. She wanted to demand to know who Osgood was seeing, where they were going and whether she considered her newly revealed relationship held any potential to last. But Kate knew that it would be highly unprofessional of her to voice any of those enquiries.

Forcing a light smile onto her face, finally acknowledging but ignoring the jealousy that was causing an intense churning in her stomach, the older woman took a breath. "Am I allowed to ask who the lucky person is?"

"Oh…" Osgood blinked in clear confusion. Apparently whatever she had been expecting to happen next, it wasn't that. "It's… Well, it's Captain Carter, actually."

"Captain Carter? Josh Carter?" Kate fought down the bile rising in her throat as she thought about the cocky soldier she had had cause to speak to several times since his arrival at UNIT a couple of months previously. She had seen him talking to Osgood at what appeared to be every opportunity he got, but she had never seriously considered the possibility that her assistant was interested in the young man. "Really?"

"Yes… He asked me out and I just thought, why not? It isn't as though I'm inundated with offers… No one else is interested in me and I just thought… he's a nice enough guy… one date won't hurt…"

A look passed between them, as though Osgood was hoping Kate would say something to prove her assumptions wrong, or convince her against the date. The blonde, for her part, was biting her tongue to prevent herself from doing anything of the sort. Internally she was screaming at herself to tell Osgood how wrong she was; how there was someone else who was definitely interested in her, someone who would be so much better for her than some self-absorbed soldier, but she couldn't. Hiding behind her professionalism, Kate stayed quiet.

"Well… I should…" Motioning towards the door, Osgood sent the blonde a final look that very nearly broke her resolve.

"Quite." Kate nodded, dropping her gaze to the open report in front of her. "Enjoy your night. I'll see you tomorrow."

As soon as the office door clicked shut and she was sure she was alone, the blonde put her head in her hands and let out a long, deep sigh. She tugged at her hair in frustration and self-loathing, knowing that she only had herself to blame when, after rather too much wine alone in her house that evening, she would be unable to banish the visions of Osgood and Captain Carter from her mind.

Standing up abruptly, Kate grabbed her things and turned off the computer monitor, deciding to leave early and get started on her self-pitying drinking sooner rather than later in the, somewhat optimistic, hopes of fending off the images that would almost definitely plague her, by falling into a deep, alcohol induced sleep as soon as she possibly could.

* * *

 _ **A/N: I got overexcited and decided to post this next part.**_

 _ **The level of flirting from Josh Carter in UNIT: Extinction was impressive and I'm sure I detected a hint of jealousy from Kate ;)**_

 _ **x**_


	3. Chapter 3

It was a blustery November afternoon and Kate was absolutely exhausted. She had spent the past fourteen hours on the edge of a large crater waiting for her team to excavate and examine the cause of the huge hole. As she strode back to the car that was waiting to take her back to the Tower of London, her mobile rang. Groaning softly as she read the name on the display before answering, she gritted her teeth and did her best to reassure the Prime Minister that the possible incursion was being dealt with in the best way they possibly could.

"Martin? Drop me off on at the top of St Katharine's Way, would you?" Kate requested tiredly as she climbed into the back of the UNIT vehicle. Seeing her driver's wary look in the mirror, she smiled tiredly. She appreciated his concern, but wasn't about to acknowledge it. "I need a coffee and, to be perfectly honest, some time to gather my thoughts before dealing with the Prime Minister again."

Smiling with understanding, her driver nodded and guided them expertly back through the dark streets towards the Tower. He indicated and pulled over at the top of the street Kate had requested, pointedly ignoring the blast of the horn from the car that had been driving far too close behind him. As the man in the red saloon sent him a very rude hand gesture, Kate frowned.

"Did you get the licence plate number?" She asked Martin quickly.

"Yes, Ma'am."

"Good… Pass it on to our friends at the Met… I'm sure there's something they can find to have a little chat to him about."

"Yes, Ma'am." Martin agreed with a small smile of amusement.

"Inform McGillop that the excavation team will be with him shortly and if anyone from Downing Street calls tell them that I'm in a meeting." Kate ordered, before opening her door and swinging her legs out. Glancing over her shoulder at the woman sitting beside her, who had stayed silent through the whole journey, she arched an eyebrow. "Coming?"

"Oh, I… Oh. Yes." Osgood fumbled with her seatbelt in a way that Kate found far too endearing to be allowed, before managing to free herself and get out of the car. "What do you need, Ma'am?"

"I don't _need_ anything." Kate informed her bluntly, pushing her hands into her coat pockets as she wandered more casually along the road than someone in her position of power had any business doing. "Like I told Martin I need a coffee and a break. I was hoping you'd keep me company."

"Oh, of course." Osgood nodded eagerly, before mentally kicking herself for acting like a teenager with a crush.

"So? I haven't had a chance to ask about your date with Captain Carter the other night." The blonde stated, forcing her tone to remain light. "Did you enjoy yourself?"

"I couldn't stop thinking about the analysis of the data on that star fragment we found." The younger woman admitted sheepishly. "I think he could tell I wasn't completely focused on him."

"Did he say anything?"

"Well, no… but he did make a comment about how much time I invest in the job."

Kate frowned. "You make it sound like it was an insult."

"I… I don't think it was, exactly." Osgood mused, thinking it over. "I think it was more… I'm not sure… like he didn't understand why I would possibly be thinking about something work related out of work hours."

"Dedication; that's why."

"Mmmm…"

"You don't sound sure?"

The brunette shook her head. "No, I… I just wonder whether I should try and be like everyone else. Leave work at the office, that sort of thing."

Pulling open the door and ushering the younger woman ahead of her into the very welcome light and warmth of Starbucks, Kate arched an eyebrow. "Why would you want to be like everyone else?"

Their conversation was put on hold while they queued and placed their orders; a skinny latte with an extra shot for Kate and a hot chocolate made with soya milk for Osgood. The blonde refused to let her subordinate pay, pulling rank and reminding her that she earned far more than the scientist. Gratefully, Osgood went to claim a table for them in the back corner, sighing deeply as she sank into the comfortable armchair after hours of being on her feet at the freezing cold site of the crater.

When Kate appeared moments later, she realised that the younger woman had fallen asleep. Taking a moment to appraise her carefully, the blonde was struck by just how beautiful the scientist was. Osgood had pulled her hair out of its neat ponytail and placed her glasses on the coffee table. She was leaning back in the armchair, with her head tilted back against the cushion and her eyes closed.

Placing the mugs on the surface of the table, Kate settled herself into her own seat, not having the heart to wake the younger woman. She sipped her coffee slowly, her eyes never once leaving Osgood's face as she finally forced herself to confront her feelings for the brunette. She could no longer fool herself that what she felt was the natural result of taking the young woman under her wing and attempting to nurture her talent. That wasn't why she felt so strongly for her at all. While she was proud of Osgood and her achievements, it was from a far more personal perspective than as a mentor.

"Sorry…" The woman in question blinked several times and pulled herself into a more upright position in her seat and blushing crimson. "Was I asleep?"

"You were." Kate agreed, an amused smile tugging at her lips. "And I'm not surprised. How much sleep did you get last night?"

Osgood rubbed her forehead tiredly after replacing her glasses and picked up her hot chocolate. "Two hours… three maybe? I stayed late to try and get a fix on those readings we were looking at yesterday and then I got the call about the crater so… well… you know the rest. I don't suppose you got much more?" She looked appalled at herself for making such a personal comment. "I'm sorry, that was–"

"Perfectly true." Kate replied with a shrug. "I got a couple more hours than you, it would seem, but not nearly enough sleep to be considered a healthy amount. The cost of dedication to our job, apparently." She looked carefully across at the younger scientist. "Which brings us back to our previous conversation. You never answered my question. Why would you want to be like everyone else if it meant being less like you?"

The brunette shrugged. "It's just… it's what people do, isn't it? You conform."

"Why?" Kate was genuinely interested in the answer.

Osgood looked stumped. "I… I'm not sure. To have what everyone wants, deep down… to have a normal life, I suppose. To be able to go home to someone at the end of a very long day and just… be understood and wanted and loved." She looked a little embarrassed as she realised who she was having the conversation with. "I don't know… I'm probably talking rubbish. I am overtired, remember."

"No. I think you're right."

"But?" Osgood smiled. "There's always a 'but'."

"But," Kate chuckled at the triumphant grin on the other woman's face as she was proved correct, "why should you have to conform, to change who you are, to have that?"

"Because where am I going to find someone who's willing to put up with me as I am now?"

Kate felt her heart clench as she released that Osgood genuinely didn't believe that anyone would, could, want her the way she was. Almost without realising what she was doing, she reached out and placed her hand over the one that was curled around the almost empty mug of hot chocolate. She squeezed it gently, trying to reassure Osgood without speaking, not trusting what might come out if she opened her mouth.

Osgood returned her weak smile, her heart thudding in her chest at the warmth of Kate's hand over hers. She hated herself for opening her mouth, cursing her exhaustion for making her spill her guts to the one person she needed to hide her feelings from the most. Her boss was looking at her with an expression in her eyes that Osgood couldn't make out. It seemed, to the brunette at least, to be something remarkably close to pity and that was something that she really couldn't handle, especially coming from Kate.

"Anyone would be lucky to have you in their life." Kate told her firmly, causing Osgood's gaze to shoot up from her their conjoined hands and meet the blonde's. "You're special, just the way you are. I–"

A shrill ringing interrupted the moment and both women seemed to realise where they were and what was happening. Retracting her hand quickly, Kate snatched up her mobile and answered it hastily. Standing up and sending Osgood a weak smile, the Head of UNIT started walking towards the doors, assuring the Prime Minister that yes, she was taking his concerns about the possible alien incursion incredibly seriously.

Following her hurriedly, Osgood sighed deeply, wishing that Kate had finished her sentence before they had been interrupted and dragged back to the situation at hand. The Prime Minister really did have the worst timing.


	4. Chapter 4

"Don't forget your inhaler."

"Stop it."

Osgood scowled at the teasing tone her sister used to remind her about the vital object that she would need to remember to pack for her overnight stay. She knew that it was intended as a dig about her ever-growing crush on Kate Stewart. Her immediate superior, Kate Stewart. Ever since their conversation about it, several months previously, the Zygon Osgood hadn't let the subject drop and, as soon as Kate had left the laboratory after asking Osgood to accompany her on an overnight trip, the woman had gone into overdrive. Now, while she was in their shared laboratory picking up the final few things needed for the trip, she was doing her upmost to ignore the teasing.

"What?" The other woman blinked at her innocently. "I'm concerned for your respiratory wellbeing."

"Of course you are."

"Well… She's basically invited you for a dirty weekend in–"

"She has not!" Osgood squeaked indignantly at her. "We're going up to Edinburgh… it makes sense to stay overnight. Besides, we might have to stay for a couple of days if things don't go to plan."

"Or if they _do_ go to plan." Her sister retorted with a snort.

"Why are you being so mean?"

There was a soft sigh and the Zygon stepped closer to the Human, rubbing her upper arms soothingly. "I'm not being mean, I'm just trying to push you into doing something about the unresolved sexual tension between you and Stewart. I mean, I'm here all the time and I swear it couldn't be more obvious that you both want each other."

"Don't be ridiculous!" Osgood laughed, her amusement not reaching her eyes. "Kate's… Kate and I'm me."

"Don't even try to fool me, sis. I'm in there, remember?" She reached out and knocked gently on her forehead. "I know what you're thinking… what you're feeling. I know that it's not just you; it's not one-sided. My observation skills are much more sensitive than yours, not to mention the fact that I'm not completely oblivious, and I've seen the way Kate looks at you; the way her pupils dilate and her breathing shallows when she's in close proximity to you, the increased pulse and occasional lapse in concentration which would indicate she's allowing her imagination to run away from her."

"Well…" Turning away, the brunette flipped through a stack of files on the workbench until she found the one she was looking for. "I don't know about any of that. Besides, I've got a–"

"Please don't end that sentence with the word 'boyfriend'." The other woman groaned. "Captain Carter is a prat. You don't like him, not really."

"I do." Osgood shot back with a frown. "I wouldn't… you know… with someone I didn't like."

"What, have sex?" Seeing her sister flinch, the Zygon smirked. "It's perfectly natural, sis. Besides, I bet you won't be thinking of much else on your dirty weekend away with the boss."

"It's not–"

"Yeah, yeah. But seriously, ditch the soldier. He doesn't make you happy and he's just standing in the way of you doing something about getting what you really want."

"I've got to go." Osgood informed her bluntly. "I'll call you when we arrive; I might need your help."

"Try and enjoy yourself!" The other brunette urged, hugging her tightly. "Don't do anything I wouldn't do."

Osgood snorted. "That doesn't limit me much, then?"

"Nope."

Shaking her head fondly, sending her sister a final wave, the scientist shouldered her holdall and set off along the corridor in the direction of her boss' office. She shifted the files in her arms, immediately allowing her mind to wander to the case that was taking them to Edinburgh. Kate had been sent some information from a breakaway group affiliated with Torchwood Two that there was possibly a backstreet market in Alien Artefacts. Something that was giving out worrying readings had triggered an alert on their scanners and Torchwood had requested UNIT's assistance in tracing and disarming the device.

"Ready?"

Osgood jumped at the soft, slightly amused tone from somewhere ahead of her and she glanced up with wide-eyes. Kate smiled and nodded towards the soldier hovering in the doorway who already appeared to be carrying his boss' overnight bag. Almost embarrassed to be doing so, the brunette handed over her own bag and fell into step beside Kate as they walked towards the main exit.

The car ride up to Scotland seemed to take no time at all. Logically, Osgood knew that it had been a good eight hours with the traffic they had hit just north of York, but she didn't feel like it had been anywhere near that long. She and Kate had discussed the possible causes of the strange phenomena that had been experienced in the Scottish capital and drawn up an action plan to implement as soon as they arrived.

They went straight to the secret base under Edinburgh Castle, Kate immediately slipping into Chief Scientific Officer role and taking charge of the situation. Osgood watched as the older woman strode through the base giving orders and being handed various snippets of information about the current situation. The brunette scientist often found herself distracted when she was working with Kate, watching in awe as her superior seemed to take everything in her stride with an unflappable calmness. Sensing that Osgood was less than focused on what she was saying, Kate shot her a small smile.

"What? Sorry, I…"

"I think perhaps we should go and track down something to eat." She suggested.

"Oh, no, Ma'am…" Osgood blushed. "I'm fine. Sorry. I'll–"

"You may be fine," the older woman nodded, motioning for someone to relieve her of the file in her hands, "but I can feel my blood sugar dropping as we speak. I'm in need of a good meal and an even better night's sleep."

Not in any position to argue as Kate grasped her arm and steered her through the corridors beneath Edinburgh Castle, Osgood couldn't help but feel relieved. She had been awake for more hours than she cared to think about and the amount of different information she had been trying to process was giving her a headache. Laughing softly at the expression on her face, Kate hailed a taxi and gave the driver the name of a restaurant she assured Osgood was excellent.

"That was fantastic, Alan, as always." Kate told their waiter as he appeared to collect their empty dessert plates a long while later. "Please send my compliments to Françoise."

"Of course. Are you ready for the bill, Ms Stewart?"

"Yes, please." She nodded and reached for her purse. Seeing Osgood rummaging around in her own bag, Kate shook her head. "It's on me."

"No, I couldn't possibly–"

"Don't be ridiculous, of course you can. I dragged you up here, it's the least I can do."

When Kate wouldn't hear of Osgood paying and physically stopped her handing over her card when Alan returned with the machine, the younger woman thanked her profusely. Kate chuckled and put her hand on her friend's arm, telling her to think nothing of it, before hailing another taxi to take them to the hotel that had been booked for them.

Osgood gaped when they arrived outside a large, grand building. Awestruck, she followed Kate up the steps and into the lobby, her mouth dropping open even more when the doormen both nodded in greeting at the blonde they so obviously knew. She couldn't believe how at ease her boss was in their imposing surroundings.

"Ms Stewart, how lovely to see you again." The woman behind the reception desk greeted them as soon as they were close enough to hear her. "Your luggage has been taken up to your usual suite."

"Thank you, Cordelia." Kate smiled warmly at the young woman, scrawling her signature lazily on the line the receptionist indicated. "I assume a bed has been made up for my associate?"

"Of course, Ms Stewart. Ms Osgood's luggage has been placed in the second bedroom." Cordelia nodded, smiling at the brunette who was clearly struggling to comprehend what was happening. "If your require anything, anything at all, we'll be more than happy to supply it. Matthew?"

A very obliging young man darted forward to show the two UNIT officials up to their suite. Kate, apparently, didn't need directing as she immediately pulled out her mobile and started tapping at the screen. Osgood, feeling totally out of place, attempted to make conversation with Matthew as he led them through the corridors, but she really didn't know what to say.

Thanking the young man, pressing something that Osgood guessed was a tip into his hand, Kate showed the brunette into the room. She chuckled at the expression on her friend's face, gently raising a hand to close Osgood's mouth.

"Inhaler." She reminded her, watching in amusement as the young woman struggled to pull the object out of her pocket and raise it to her mouth. After a couple of puffs, Kate indicated to one of the doors which led off the main room. "The bathroom is through there and your bedroom is the second door on the right."

"I…"

"We should get an early night." Kate suggested. If Osgood wasn't very much mistaken, the confidence that had been written all over her face all day had been replaced with something else. "We've got a busy few days ahead of us."

"Yes." The brunette agreed with a nod. She chewed her lip nervously. "I… thank you, for this, Kate. I've never been…"

"The UNIT Admin Department insist on sending me here. I've told them that I'd be quite happy in a Travelodge, but they won't listen."

"There's a bit of a difference between this and a Travelodge." Osgood pointed out with a smile.

"There is." Kate agreed. "Listen, Osgood, I… I wanted to…"

She stepped forward, the uncertainty on her face becoming more prominent. Osgood's breath hitched in her chest as she looked into her superior's eyes. Kate's gaze flickered down to the brunette's lips for a moment and Osgood was sure that she was about to kiss her. Her heart leapt in her chest and she took another step closer, unable to believe it was finally happening.

A loud ringing caused both women to jump and spring apart. Looking around for the cause of the sound, Osgood groaned as she realised that it was her mobile. Fumbling in her pockets she finally pulled out the offending object and felt her heart sink as she read the name on the display.

"I'm sorry, Kate… it's Josh, I…"

Kate smiled tightly, cursing Captain Carter and not for the first time. "Of course. I'll leave you to speak to him. See you in the morning."

As she disappeared through her bedroom door and closed it behind her, Osgood sighed. Then she accepted the incoming call, allowing her eyes to slip closed as she greeted her boyfriend with as much enthusiasm as she could manage.


	5. Chapter 5

"Come on, Nell!" Bonnie called through her sister's bedroom door exasperatedly. She glanced at her watch for what felt like the twentieth time in the last five minutes. "The taxi will be here in ten minutes and I want to see your dress."

"I feel stupid!" The other woman called back.

"You'll look fantastic." Bonnie replied firmly. "I know that because I look fantastic."

"So modest, aren't you?"

The brunette in the hallway chuckled. "What's the point in being modest when I know I look good?" She rolled her eyes at the still closed door. "Come on, I wanna see!"

With a loud sigh, the woman in her bedroom slowly opened her door and stepped out so that her sister could appraise her thoroughly. She was wearing a red skater dress with three quarter length sleeves. The top layer of the dress was lacy and Osgood was tugging at the hem, which fell just above her knees, self-consciously.

"See, fantastic, I told you!" Her sister replied with a broad grin. "What about me?"

Osgood scrutinised her sister carefully. Bonnie's dress was far more risqué than hers and showed a lot more flesh than the brunette was comfortable with. She wasn't entirely sure she liked it, considering that they were, essentially, the same person and so their colleagues would, by default, have seen far more of her body than she wanted them to.

The dress was black and figure hugging, showing every one of the scientist's curves. It ended several inches above the knee and had only one strap, sequined and sparkly, over Bonnie's right shoulder. Osgood tilted her head slightly as she followed the familiar legs down to where they ended in towering patent stilettos.

"Wow…"

"I know, right?" Bonnie grinned, doing a twirl. "We're definitely gonna show Josh Carter what he's missing."

" _I_ broke up with _him_ , remember?" Osgood pointed out with a tired sigh.

"Not the point." Her sister said dismissively, grabbing her by the hand and pulling her through the flat to wait by the front door. Osgood barely managed to switch off the lights and make sure her keys and inhaler were in her clutch bag before Bonnie slammed the front door behind them. "Besides, it's not really Josh you want to notice you, is it?"

"Stop it, Bonnie." Osgood warned. "Don't you dare say anything–"

"I'm not making any promises." The other woman teased, checking her make up in her compact.

With a deep sigh, Osgood climbed into the back of the waiting taxi and gave the address of the hotel where UNIT's Christmas party was being held. She twisted her hands in her lap nervously as the car drove through the streets, not showing any of her usual delight at the twinkling lights and festive decorations. She was too anxious to get to the venue and set eyes on Kate. Bonnie was right, she was far more interested in what her boss thought of her appearance than her ex-boyfriend.

The doorman smiled at the two women as they showed him their invites and ushered them into the lobby. From there, a porter directed them to the ballroom where the function was being held. Bonnie shot her sister a broad grin as they opened the double doors and stepped into the room. Osgood gasped at the sight that met her eyes. It was truly beautiful.

"Osgoods!"

Osgood's heart leapt at the familiar voice and she turned her head in the direction of the sound eagerly. Beside her, Bonnie chuckled quietly, squeezing her sister's hand. _Act cool, Nell._ She ordered silently, receiving the mental equivalent of a thump in return.

"What do you think?" Kate asked as she joined them, motioning at the ballroom.

"Beautiful…" Osgood murmured.

"The room isn't bad, either." Bonnie added with a snigger, noticing that her sister's eyes hadn't left Kate at all.

The blonde was also wearing a black dress, but hers had a halter neck and a fitted bodice, with a flowing skirt that ended at her knees. She cleared her throat self-consciously at the brunette's words and quickly rearranged her expression to a more nonchalant one.

"You both look lovely. I don't think I've ever seen you in a dress, before."

"You too, Ma'am…" Osgood managed to say, clamping her lips together before she said anything else.

"Well, no. You've never actually attended a UNIT function before." Kate teased gently.

"No, I was boring before. That's all changed now, right, sis?" Bonnie replied, winking at her sister. "We're single and ready to mingle."

The other brunette winced. "Never say that again."

"Single?" Kate asked, her eyes fixed on Osgood interestedly. "Well…" She cleared her throat and seemed to pull herself together. "I'd better…"

The two women watched as she turned and walked away, making a beeline towards Colonel Shindi and taking a glass of champagne off a passing waiter in the process. Bonnie watched with interest as the blonde downed most of the glass in one gulp, before reaching for another.

"Drink?" She asked her sister innocently.

"No, I don't think–" Osgood started, but was cut off as Bonnie pushed a canapé into her mouth and a glass of champagne into her hand.

"Drink up, there's a good girl." Bonnie advised, before whirling away towards the dance floor.

Left alone just inside the ballroom, the shy brunette looked around nervously. She pushed her glasses, which she had refused to remove despite her sister's best efforts to convince her to do so, further up her nose and looked around for either Malcolm or McGillop. She spotted her friends sitting at a table at the corner of the dance floor and headed towards them quickly.

They smiled warmly at her, showering her with compliments about her appearance, which the woman brushed off embarrassedly. They watched the other partygoers enjoying themselves before Malcolm tentatively asked Osgood if she'd like to dance. Bonnie had been thoroughly enjoying herself, being whirled around the floor by various UNIT soldiers and officials and Osgood, caught by a sudden moment of uncharacteristic longing to be like her apparently fearless sister, decided that she would very much like to dance with her friend.

He held out a hand, ever the gentleman, which Osgood took with a smile. He led her out into the centre of the dance floor and gingerly put one hand on her waist, while gripping her hand firmly with the other. Osgood chuckled lightly at the concentration on his face as they danced, making sure that he didn't step on her feet. She glanced over his shoulder to where Kate was dancing with Colonel Shindi, shivering as the blonde glanced in her direction at the same moment and their eyes met. Unsure how long they had been staring at each other, the brunette jumped as Malcolm cleared his throat.

"Osgood, I…" He cleared his throat again, evidently nervous about something. "I… wanted to ask whether you… well… would you be willing… it doesn't matter if you're not, but I wanted to…"

Suddenly the brunette guessed where his rambling was going and blushed. "Malcolm… I'm flattered, but I…"

"Of course." He looked away, blushing even more than his friend. "Silly of me."

"No, Malcolm, you don't understand." Osgood tried again. "I really am flattered, I just… there's someone else and…"

"Of course. You and Captain Carter, I should have–"

"No… she's a woman."

"Oh." Malcolm's eyes widened almost comically, then he glanced over his shoulder quickly. When his gaze returned to Osgood, he was smiling. "Kate, of course."

"What?" The young woman gaped at him. "How did you…?"

"It's obvious." He replied with a shrug, apparently much happier about being turned down now. "And of course you've been keeping it quiet at work. It all makes sense."

"No, Malcolm, that's not…"

"I'll leave you to it." He told her suddenly.

Osgood frowned in confused as he let go of her and headed back to the table they'd been sitting at. It was only when a gentle hand was laid on her waist that she realised someone had moved to join her. Turning quickly, she almost squeaked as she realised Kate was incredibly close and was smiling at her.

"Warm in here, isn't it?" The blonde pointed out lightly, leading the way off the dance floor. She liberated two glasses of champagne from a passing waiter and handed one to her friend.

"It is." Osgood agreed, taking a sip of her drink. "My sister was right… you do look beautiful."

"I seem to recall she said that the room looked beautiful. It was you who commented on my appearance, wasn't it?"

The brunette blushed. "Oh, well… yes. Because… you do… look very beautiful, I mean. You always do though, so…"

"Thank you." Kate said, taking pity on the younger woman. "Don't tell your sister, but I much prefer this dress." She admitted in a low voice, reaching out and stroking the lace of the dress just below the neckline. Osgood's knees almost gave way. "You look stunning."

"Oh, I… thank you."

"Osgood… I really…"

"Nell!" The two women turned at the shout and spotted Bonnie hurrying towards them, pushing people aside in her haste. She had lost her shoes somewhere, but she still managed to trip over, crashing onto the carpeted floor at their feet. From the ground, she let out a loud giggle. "I love champagne!"

Osgood sighed and crouched to help her up. "I'd better get her home."

"Yes, that would probably be best." Kate agreed, disappointment at having their moment interrupted evident in her tone.

As she helped the young women through the lobby and into the back of the taxi, Kate cursed the time she had wasted that evening building up the courage to tell Osgood how she felt. Now it was too late and she was already regretting it.

"Night, Kate." Osgood said softly, shooting her a wistful look through the open window of the car.

The blonde returned the smile, equally sadly. "Goodnight."


	6. Chapter 6

Three days after the Christmas party, Kate found herself staring angrily at the monitor of her computer. Her mood had nothing to do with the report that was open on the screen but was entirely caused by the way the party had ended. She hadn't stayed long after the Osgoods had left, kicking herself for not acting sooner and telling the younger woman how she felt about her.

A knock on her door alerted her to the presence of someone outside and, through the glass, she could see that it was the woman who was almost constantly on her mind. Sucking in her breath sharply, Kate called Osgood in, looking expectantly up at her over the rims of her glasses. She saw the very familiar blush spreading over the brunette's cheeks and frowned lightly as Osgood looked down to avoid meeting her eyes.

Something flared up inside her and Kate decided that she had finally had enough. Life was far too short to waste dancing around each other and regretting missed opportunities. They could die tomorrow, for goodness sake. No, the blonde decided firmly, there was no time like the present.

"This is getting ridiculous." She announced, much to Osgood's surprise, marching around her desk and stopping directly in front of the younger woman. The brunette's eyes widened in confusion and she instinctively reached for her inhaler in her pocket. "How hard can it be to tell you how much I–"

Somehow knowing exactly what the older woman was trying to tell her, perhaps from the almost desperate expression on her face, Osgood screwed up all of her courage and lurched forward, planting a firm kiss on her superior's lips. It only lasted a moment and then Osgood stepped backwards, chewing her lip as Kate stared at her in complete surprise. Panic flared up inside the young woman's chest as her boss didn't say or do anything and she feared that she had read the signals completely wrong.

"Kate, I… I'm so sorry. I'll just…"

Turning, Osgood made to flee out of the office and back to the safety of her laboratory and her sister, her cheeks flaming scarlet and conveying her total mortification. She hadn't taken a single step, however, before she felt a hand closing around her wrist and Kate pulled her round. Osgood didn't have time to apologise again before Kate's lips were on hers and one arm had wrapped around her waist while Kate's other hand wound itself into her hair.

Osgood sighed into the kiss, wrapping her own arms around the blonde and pulling her impossibly closer. She didn't want to let Kate go in case the kiss ended and was never repeated. She felt like she had been waiting for this moment her whole life and she couldn't quite believe it was actually happening. Osgood thought she might combust with happiness.

"Wow…" Kate breathed when they finally broke apart. She kept her grip on Osgood's hips, as though afraid she would disappear if she let go.

"Quite." The younger woman agreed, nuzzling her nose against the blonde's and pressing a soft, chaste kiss against her lips.

"You have no idea how long I've wanted to do that."

"It's probably not as long as I've wanted to." Osgood told her with a grin.

"I wouldn't count on it." Kate whispered, tucking a stray strand of the brunette's hair behind her ear. "You're so beautiful…"

Osgood flushed crimson. "Oh… no… I'm not…"

"You are to me."


End file.
